Electric weft detector



Dec. 31, 1935. E R E 2,025,863

ELECTRIC WEFT DETECTOR Filed Jan. 20,1934 2 Sheets-Sheet v Dec. 31,1935. E. R. HOLMES ELECTRIC WEFT DETECTOR Filed Jan. 20, 1954 2Sheets-Sheet 2 Patented Dec. 31, 1935 UNITED STATES PATENT OFFEQEELECTRIC WEFT DETECTOR Application January 20, 1934, Serial No. 707,559

9 Claims.

This invention relates to improvements in electrical weft detectors forlooms and it is the general object of the invention to provide adetector which exerts a very light pressure on non-indicating detectingbeats of the loom but controlled to increase the pressure on indicatingbeats to insure better contact.

A well-known form of electrical detector employs detector wires orelectrodes which project through the front wall of the shuttle to engagethe yarn. A sufficient supply of weft keeps the electrodes insulatedfrom each other, but when the supply is exhausted, a metallic ferrule onthe bobbin or quill is uncovered and electrically connects theelectrodes to close an external circuit the effect of which is to bringabout either loom stoppage or weft replenishment. Electrical detectorsare usually employed with fine yarn, and the pressure of the detectorsagainst the yarn is reduced to a minimum. It is found in certaininstances, however, that a pressure which is sufliciently light for avery fine weft is hardly enough to hold the electrodes against theferrule tightly enough to insure good contact. It is an important objectof my present invention to permit light pressure on the electrodes whenthe circuit is not completed, but to cause the electrode to exert agreater pressure on the ferrule as soon as any current whatever flowsthrough the electrodes.

In a form of the invention set forth hereinafter I employ a magnet to bein a circuit with the electrodes and so arranged as to move a frictiondevice against the sliding electrodes to retard their movement as soonas the circuit is closed. Under these conditions, should the-contact atthe ferrule be very light, the friction due to the armature will cause abetter contact to exist between the electrodes and the ferrule, therebyinsuring the flow of suflicient current to energize the loom controllingelectromagnetic device.

In another form of the invention a magnetic field is caused to resistmovement of a core at initial indication, and the core is connected tothe detector electrodes, thereby holding the latter against the ferruleto increase the pressure of contact.

In both forms of my invention, the detector is so controlled andconstructed that an initial effort on the part of the detector tendingto give an indication will produce a magnetic field which is effectiveto improve the contact and thereby give a more certain indication.

With these and other objects in view which will appear as thedescription proceeds, my invention resides in the combination andarrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings'wherein aconvenient embodiment of myinvention is set forth,

Fig. 1 is a side elevation of a part of a loom having the preferred orfirst form of my invention applied thereto,

Fig. 2 is a top plan view of a part of the structure shown in Fig. 1, I

Fig. 3 is a side elevation of the first form of my invention,

Fig. 4 is a front elevation of the structure shown in Fig. 3 looking inthe direction of arrow 4, Fig. 3,

Fig. 5 is a diagrammatic view of the circuit for the-first form of theinvention,

Fig. 6 is a vertical section on line 6-6 of Fig. 4,

Fig. 7 is a view similar to Fig. 3, but showing a modified form of theinvention, and

Fig. 8 is a plan view looking in the direction of arrow 8, Fig. 7.

Referring to the drawings, the loom I is provided with a lay ll having ashuttle box l2 with binder l3 and box back I 4 between which the boxedshuttle S may be located when the "lay is in forward position. Theshuttle has a weft compartment l and the front wall thereof is providedwith a slot l6 which exposesa part of quill or bobbin H. As shown hereinthe bobbin is provided. with a metallic ferrule l8 which is normallycovered by the weft W but which is uncovered when the supply of weft isdepleted to a point rendering a change in loom operation necessary.During the normal operation the lay moves the boxed shuttle forwardlywhile stationary with respect to the lay, thereby permitting weftdetecting.

The detector mechanism is of the electrical type and comprises a body 20of insulating material in which are slidably mounted detector wires orelectrodes 2| and 22, each provided witha detecting head 23. Each wirepasses through acompartment 24 formed within the body 20 and issurrounded by a light coil spring 25 tending to hold the latteryieldingly in rearward position toward the advancing lay. .Each wirepasses through a nut or circuit terminal 26 which affords bearing forthe front end of the wire and also provides means for electricallyconnecting the sliding wire with a circuit to be described. The

part of the detector already described may be similar to that shown inthe Payne Patent No. 1,92%,197.

In the first or preferred form of my invention, shown in Figs. 1 to 6, afixed support is secured in any approved manner to the loom and has thebody 20 fastened thereto with the electrodes in alignment with the slotIS. The sliding detector wires are extended forwardly as at to lie overa pad'36 of insulating material carried by an armature 37 located to beattracted by the cores 38 of electromagnets 39. The latter are held by aclip 40 which may be welded or in any other way secured to a bracket Mheld to the support 30 by screws 42. As shown in the drawings the body20 may also be secured to this bracket 4| although the particular mannerof mounting the detector proper and the electromagnets is immaterial.

The top 43 of the bracket 4| carries a pair of spaced vertical rods Mthreaded into said top and held in adjusted position by nuts 45. Cotterpins 46, or the like, hold the armature 31 at the desired adjustedposition relatively to the electrodes, or wires 2| and 22.

In Fig. 5 I have shown a circuit which is closed by a bare ferrule l8.When the ferrule contacts with the wires 2| and 22 the following circuitwill be closed: source of electric power 59, wire 5|, sliding electrode2|, ferrule i6, sliding electrode 22, wire 52 the magnets 39 which areconnected in series, wire 53 to the ground, and

from the ground by way of wire 54 to an electromagnetic loom controller55, and from thence by wire 56 back to the source of power. Current willflow in this circuit as soon as the electrodes contact with the ferrule,and will energize the magnets 39, whereupon the armature 31 will beraised to the dotted line position shown in Fig. 4 to lift the frictiondevice 36 against the extended ends 35 of the electrodes. Thereafter,forward movement of the electrodes is resisted with resultant increasedpressure between the electrodes and the ferrule. In this way assuranceis given that even though a light contact is initially established atthe ferrule, nevertheless, the remainder of the detecting operation willbe improved by increasing the pressure against the ferrule as described.

In the modified form set forth in Figs. '7 and 8 I illustrate anarrangement whereby the circuit is maintained throughout the time thattheferrule has contact with the electrodes. In carrying out this form ofmy invention I employ the same type of weft detector as that shown inFigs. 3 and 4, with detector wires 2| and 22 to be electricallyconnected when engaging a bare ferrule I8.

Unlike the first form, however, I provide for yieldingly holding theelectrodes rearwardly by a spring 60 which acts between a stand 6| and alever 62 pivoted as at 63 to a part of the stand. The upper end of thelever has pivoted thereto a pad of insulating material 64 on a carrier64a which is free to swing in a horizontal plane about a pin 62a on arm62 and rests on a shoulder 65 also on the lever. The pad 64 engagestheforward ends of the detector wires 2| and 22 and transmits theyielding force of spring 6!] to said wires, tending to hold themrearwardly. If desired I may incline that face of the pad which engagesthe wires so that as the lever swings rearwardly around its pivot 63 thewires will be given a slight upward thrust tending always to hold themin good electrical contact with the guides 26. Forward movement of thesurface to be detected will push the pad to the right as viewed in Fig.7 against the action of spring 66, and after the lay passes front centersaid spring will push the wires rearwardly, thus holding them againstthe surface to be detected or the ferrule l8, as the case may be, duringrearward motion of the lay.

In order to increase the resistance to the mo- 5 tion of the electrodeswhen indicating weft exhaustion, I provide a solenoid 10 mounted on thestand 6| and having a core 12 attached by means of a link 13 to thelever 62. Part of the core will normally lie outside the solenoid, asshown in 16 Fig. '7, so that the magnetic field will tend to move thecore to the left, as viewed in Fig. 7, or in a direction to hold theelectrodes 2| and 22 against the surface being detected. Shoulders 80 onthe detector wires limit their rearward 15 motion in both forms of theinvention.

The wiring for the solenoid is not specifically set forth herein, but issubstantially the same as that shown in Fig. 5, the solenoid replacingthe magnets 39. When this circuit is closed at 20 exhaustion of weft, asalready described, resultant magnetic field created by the solenoid willattract the core 12, thereby increasing the pressure between thedetector wires and the ferrule. Since the core is normally helddisplaced 25 with respect to the magnetic field by the shoulders 86, itwill always tend to establish a better contact at the ferrule whenevercurrent is flowing through the electrodes. It will be noted that, unlikethe disclosure of the first form, the wires 30 are not subjected to anyopposed force tending to prevent them from following the ferrule whenthe lay moves rearwardly. In the second form of the invention,therefore, the entire time during which-the ferrule could have contactwith the detectors can be employed to set the electromagnetic device 55.

From the foregoing it will be seen that I have provided means whereby aweak and insufficient current due to a defective initial contact at the440 ferrule can be utilized to improve the contact and thereby result inthe fiow of sufficient current to energize the loom controller 55. Itwill be seen that this result is accomplished by causing the initialfiow of current to produce a magnetic 45 field which is thereby renderedeffective to increase the pressure on the electrodes. It will also beseen that in each form of the invention the sliding wires are subjectedto an upward force exerted laterally of their length which 50 holds themin close sliding engagement with the guides or terminals 26, therebyfurther insuring proper contacts throughout the circuit. In this way Inot only insure correct contact at the bobbin but also at those fixedpoints from which 55 the current is tapped off to feed the loomcontroller 55. When weaving with very fine yarns thefeeler pressure canbe reduced to a minimum to avoid abrasion of the yarn, but when contact60 occurs at weft exhaustion, the pressure is automatically increased.

Having thus described my invention it will be seen that changes andmodifications may be made therein by those skilled in the art without 65departing from the spirit and scope of the invention and I do not wishto be limited to the details herein disclosed, but what I claim is:

1. In a weft detector for a loom having a surface to be detected, asliding electric detector to engage and be moved by the surface, afriction device to have engagement with the detector, andelectromagnetic means brought into action by an indication of exhaustionof weft given by the detector and effective to move the friction deviceagainst the detector to increase the pressure between the detector andsurface.

2. In a loom operating with a weft supply and an electric conductingferrule which is normally covered by the supply but uncovered when thesaid supply becomes substantially depleted, a pair of electric contactdevices engaging the weft supply with a given normal pressure ondetecting non-indicating beats of the loom, electromagnetic meansbrought into action when the contact devices engage the conductingferrule, and a friction pad controlled by the electromagnetic means toexert lateral pressure on the contact devices.

3. In an electric weft detector for looms having a metallic surface tobe uncovered as weft exhaustion approaches, a sliding detector to haveelectric contact with the metallic surface, a circuit terminal throughwhich the detector slides, and electro-magnetic means to be energized bycontact of the detector andmetallic surface to exert a lateral force onthe detector to effect increased contact pressure between the detectorand circuit terminal.

4. In an electric weft detector for a loom operating with an electricconducting surface to be uncovered as weft exhaustion approaches, asupporting body, a metallic detector slidabl'e with respect to the body,a circuit terminal carried by the body to have sliding contact with thedetector, and electromagnetically operated means rendered eifective byelectric contact between the detector and the conducting surface toexert a force on the detector in a direction to move the latter intoclose contact with the circuit terminal.

5. In an electric weft detector for a loom operating with an electricconducting surface to be uncovered as weft exhaustion approaches, asliding electric detector element to engage and be moved by theconducting surface, a circuit terminal element having sliding engagementwith the detector element when the latter is moved by the conductingsurface, and electro-magnetically operated means rendered effective byelectric contact between the detector element and the conducting surfaceto exert a force tending to cause relative motion of the elements towardeach other in a direction lateral with respect to the direction ofmotion of the detector element to effect close sliding contact betweenthe elements.

6. In an electric weft detector for looms having a metallic surface tobe uncovered as weft exhaustion approaches, a sliding detector elementto have electric contact with the metallic surface,

a circuit terminal element with respect to which the detector slides,and electro-magnetic means to be energized by contact of the detectorand metallic surface to exert a lateral force on one element tending tomove the same toward the other element to effect increased contactpressure between the elements, and to exert a force on the detectorelement tending to hold the latter firmly against the metallic surface.

'7. In an electric weft detector for a loom operating with an electricconducting surface to be uncovered as weft exhaustion approaches, asliding electric weft detector to have engagement with the conductingsurface, a circuit terminal to have sliding engagement with thedetector, and electro-magnetically operated means rendered effective bycontact between the detector and the conducting surface tending to holdthe detector against the detecting surface and also cause relativelateral movement between the detector and the circuit terminal to theend that the electro-magnetically operated means effects close electriccontact between the detector and the conducting surface and also betweenthe detector and the circuit terminal.

8. In an electric weft detector for a loom operating with an electricconducting surface to be uncovered as weft exhaustion approaches, anelectric weft detector to be moved by the conducting surface, a circuitterminal to have sliding engagement with the detector when the latter ismoved by the conducting surface, an electromagnetic device to beenergized by electric contact between the detector and the conductingsurface, and means operatively related to the electro-magnetic deviceand detector tending to resist movement of the latter by the conductingsurface and also tending to move the detector laterally into closesliding electrical engagement, with the circuit terminal.

9. In an electric weft detector for a loom operating with an electricconducting surface to be uncovered as weft exhaustion approaches, an

electric weft detector to be moved by the conducting surface, a circuitterminal to have sliding engagement with the detector when the lattermoves, and electro-magnetically operated means tending to resistmovement of the detector by the conducting surface and also exerta'force tending to produce relative lateral movement between thedetector and the circuit terminal in a direction to cause close electricengagement between said detector and circuit terminal.

ELBRIDGE R. HOLMES.

